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1.
Ann Bot ; 120(4): 539-549, 2017 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-28961707

RESUMEN

Background and Aims: Investigating species distributions across geographic barriers is a commonly utilized method in biogeography to help understand the functional traits that allow plants to disperse successfully. Here the biogeographic pattern analysis approach is extended by using chloroplast DNA whole-genome 'mining' to examine the functional traits that have impacted the dispersal of widespread temperate forest species across an intermittent seaway, the 200 km wide Bass Strait of south-eastern Australia. Methods: Multiple, co-distributed species of both dry and wet forests were sampled from five regions on either side of the Strait to obtain insights into past dispersal of these biomes via seed. Using a next-generation sequencing-based pool-seq method, the sharing of single nucleotide polymorphisms (SNPs) was estimated between all five regions in the chloroplast genome. Key Results: A total of 3335 SNPs were detected in 20 species. SNP sharing patterns between regions provided evidence for significant seed-mediated gene flow across the study area, including across Bass Strait. A higher proportion of shared SNPs in dry forest species, especially those dispersed by birds, compared with wet forest species suggests that dry forest species have undergone greater seed-mediated gene flow across the study region during past climatic oscillations and sea level changes associated with the interglacial/glacial cycles. Conclusions: This finding is consistent with a greater propensity for long-distance dispersal for species of open habitats and proxy evidence that expansive areas of dry vegetation occurred during times of exposure of Bass Strait during glacials. Overall, this study provides novel genetic evidence that habitat type and its interaction with dispersal traits are major influences on dispersal of plants.


Asunto(s)
Dispersión de Semillas , ADN de Cloroplastos/genética , Ecosistema , Bosques , Genoma de Planta/genética , Océanos y Mares , Polimorfismo de Nucleótido Simple/genética , Dispersión de Semillas/fisiología , Australia del Sur
2.
Br J Cancer ; 108(10): 2178-85, 2013 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-23571737

RESUMEN

BACKGROUND: Most of the heritable risk of glioma is presently unaccounted for by mutations in known genes. In addition to rare inactivating germline mutations in TP53 causing glioma in the context of the Li-Fraumeni syndrome, polymorphic variation in TP53 may also contribute to the risk of developing glioma. METHODS: To comprehensively evaluate the impact of variation in TP53 on risk, we analysed 23 tagSNPs and imputed 2377 unobserved genotypes in four series totaling 4147 glioma cases and 7435 controls. RESULTS: The strongest validated association signal was shown by the imputed single-nucleotide polymorphism (SNP) rs78378222 (P=6.86 × 10(-24), minor allele frequency ~0.013). Confirmatory genotyping confirmed the high quality of the imputation. The association between rs78378222 and risk was seen for both glioblastoma multiforme (GBM) and non-GBM tumours. We comprehensively examined the relationship between rs78378222 and overall survival in two of the case series totaling 1699 individuals. Despite employing statistical tests sensitive to the detection of differences in early survival, no association was shown. CONCLUSION: Our data provided strong validation of rs78378222 as a risk factor for glioma but do not support the tenet that the polymorphism being a clinically useful prognostic marker. Acquired TP53 inactivation is a common feature of glioma. As rs78378222 changes the polyadenylation signal of TP53 leading to impaired 3'-end processing of TP53 mRNA, the SNP has strong plausibility for being directly functional contributing to the aetiological basis of glioma.


Asunto(s)
Neoplasias Encefálicas/genética , Glioma/genética , Penetrancia , Polimorfismo de Nucleótido Simple , Proteína p53 Supresora de Tumor/genética , Neoplasias Encefálicas/epidemiología , Estudios de Casos y Controles , Europa (Continente)/epidemiología , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Glioma/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/fisiología , Procesamiento de Término de ARN 3'/genética , Proteína p53 Supresora de Tumor/fisiología , Estados Unidos/epidemiología
3.
Conserv Biol ; 27(6): 1468-77, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23869490

RESUMEN

The conservation implications of large-scale rainforest clearing and fragmentation on the persistence of functional and taxonomic diversity remain poorly understood. If traits represent adaptive strategies of plant species to particular circumstances, the expectation is that the effect of forest clearing and fragmentation will be affected by species functional traits, particularly those related to dispersal. We used species occurrence data for woody plants in 46 rainforest patches across 75,000 ha largely cleared of forest by the early 1900s to determine the combined effects of area reduction, fragmentation, and patch size on the taxonomic structure and functional diversity of subtropical rainforest. We compiled species trait values for leaf area, seed dry mass, wood density, and maximum height and calculated species niche breadths. Taxonomic structure, trait values (means, ranges), and the functional diversity of assemblages of climbing and free-standing plants in remnant patches were quantified. Larger rainforest patches had higher species richness. Species in smaller patches were taxonomically less related than species in larger patches. Free-standing plants had a high percentage of frugivore dispersed seeds; climbers had a high proportion of small wind-dispersed seeds. Connections between the patchy spatial distribution of free-standing species, larger seed sizes, and dispersal syndrome were weak. Assemblages of free-standing plants in patches showed more taxonomic and spatial structuring than climbing plants. Smaller isolated patches retained relatively high functional diversity and similar taxonomic structure to larger tracts of forest despite lower species richness. The response of woody plants to clearing and fragmentation of subtropical rainforest differed between climbers and slow-growing mature-phase forest trees but not between climbers and pioneer trees. Quantifying taxonomic structure and functional diversity provides an improved basis for conservation planning and management by elucidating the effects of forest-area reduction and fragmentation. Efectos de la Forma de Crecimiento y Atributos Funcionales en la Respuesta de Plantas Leñosas al Desmonte y Fragmentación de Bosque Lluvioso Subtropical.


Asunto(s)
Conservación de los Recursos Naturales , Agricultura Forestal , Desarrollo de la Planta , Biodiversidad , Nueva Gales del Sur , Dispersión de Semillas , Especificidad de la Especie , Clima Tropical
4.
Sci Rep ; 13(1): 15335, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37714874

RESUMEN

The fatigue response of additively manufactured (AM) specimens is mainly driven by manufacturing defects, like pores and lack of fusion defects, which are mainly responsible for the large variability of fatigue data in the S-N plot. The analysis of the results of AM tests can be therefore complex: for example, the influence of a specific factor, e.g. the building direction, can be concealed by the experimental variability. Accordingly, appropriate statistical methodologies should be employed to safely and properly analyze the results of fatigue tests on AM specimens. In the present paper, a statistical methodology for the analysis of the AM fatigue test results is proposed. The approach is based on shifting the experimental failures to a reference number of cycles starting from the estimated P-S-N curves. The experimental variability of the fatigue strength at the reference number of cycles is also considered by estimating the profile likelihood function. This methodology has been validated with literature datasets and has proven its effectiveness in dealing with the experimental scatter typical of AM fatigue test results.

5.
Rev Neurol (Paris) ; 167(10): 699-703, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21885076

RESUMEN

Many known oncogenic signaling pathways involved in gliomagenesis have strong consequences on tumor cell metabolism, and promote the switch from oxidative phosphorylation to aerobic glycolysis, for ATP generation. However, the interest on metabolism has been recently renewed by the discovery of recurrent mutation of IDH1 genes by systematic sequencing of a glioblastoma series. IDH1 encodes the cytoplasmic NADP dependent isocitrate dehydrogenase1 that catalyzes the oxidative decarboxylation of isocitrate into α-ketoglutarate. IDH1, more rarely IDH2, is mutated in 40% of gliomas (roughly 70% of low-grade gliomas, 50% of grade III, and 5 to 10% of primary glioblastomas). IDH1/IDH2 mutations are associated with genomic profile, being present in nearly all the 1p19q codeleted gliomas, and virtually absent in gliomas with EGFR amplification. It is a strong and independent predictor of survival, whatever grade considered. IDH1/IDH2 mutation results in a new enzymatic activity transforming α-ketoglutarate into 2-hydroxyglutarate (2-HG). The oncometabolite 2-HG accumulates in the cell and acts as a competitive inhibitor of many α-ketoglutarate dependent cellular reactions. The cellular consequences of this mutation offer potential targets for the development of novel therapeutics.


Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Glioma/genética , Glioma/metabolismo , Isocitrato Deshidrogenasa/genética , Mutación/fisiología , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Transformación Celular Neoplásica , Humanos , Isocitrato Deshidrogenasa/efectos de los fármacos
6.
New Phytol ; 188(3): 868-78, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20659301

RESUMEN

• Although founder populations often have low diversity, they can potentially serve as stepping stones for further colonization, as refugia during nonoptimal times and as a source of specialized adaptive potential. The demonstration of such potential within natural plant populations has proven to be particularly difficult. Our investigation into a geographically disjunct population of a heterostylous shrub, Erythroxylum pusillum, aims to explore the evolutionary and ecological consequences of being an isolated founder population. • Microsatellite-based analyses were used to find evidence for, and trace the origins of, a severe founder effect. Molecular and spatial evidence was used to quantify clonality and to discover proof of somaclonal mutations. • We describe the unprecedented case of an isolated population that persisted through historical environmental fluctuations and in marginal habitat through vegetative spread, and is counteracting the lack of sexual recombination and gene flow through somatic mutation. • Our findings advance our understanding of how founder populations survive, differentiate and evolve. They also have implications for how conservation agencies should perceive and manage previously considered 'dead-end' populations.


Asunto(s)
Erythroxylaceae/genética , Efecto Fundador , Flujo Génico , Aptitud Genética , Mutación , Reproducción Asexuada/genética , Ecosistema , Genes de Plantas , Variación Genética , Repeticiones de Microsatélite , Recombinación Genética
7.
J Neurosurg Sci ; 54(4): 159-62, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21423087

RESUMEN

Metastasis of the inner auditory canal is a really rare event. Clinically, it usually presents with rapid worsening cranial nerve palsy. Authors present a review of the literature reporting clinical features, radiological findings, intraoperative aspects of an illustrative case. A 56-year-old female patient presented with a peripheral facial nerve palsy. MRI showed two left p-fossa tumors whose one into the inner canal. Rapid worsening of facial damage despite corticosteroid treatment and the possibility to remove both tumors in the same surgical step suggested authors to operated on the patient. Intraoperatively, inner canal tumor looked totally involving the VII-VIII nerve complex so surgical extirpation was only partially feasible. Posterior wall drilling of the meatus was performed which improved facial palsy. Leptomeningeal spinal seeding occurred and spinal irradiation was performed. The case highlights the importance of maintaining a high degree of awareness of the auditory canal metastasis in patients with a previous history of malignancy who develop a rapid progressive peripheral VII nerve palsy. Furthermore, our case and literature data suggest that inner canal metastasis is a distinct entity from temporal bone and ponto-cerebellar angle metastasis on the base of the peculiarity of clinical features, prognosis, therapeutic strategies. In fact, inner canal metastases usually arise in patients apparently cured, and they imply a better prognosis even if with an higher risk of leptomeningeal seeding. Moreover, surgery rarely allows the removal of the lesion, also if symptoms relief may be achieved, as in our case.


Asunto(s)
Neoplasias de la Mama/patología , Neoplasias del Oído/diagnóstico , Neoplasias del Oído/secundario , Oído Interno , Neoplasias del Oído/cirugía , Oído Interno/patología , Parálisis Facial , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , Resultado del Tratamiento
8.
Mol Ecol ; 18(7): 1422-38, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19284473

RESUMEN

This study investigates patterns of genetic connectivity among 11 co-distributed tropical rainforest tree species from the genus Elaeocarpus across a biogeographic barrier, the Black Mountain Corridor (BMC) in the Australian Wet Tropics (AWT). We analysed a combination of allelic and flanking region sequence data from microsatellite markers, and evaluated the relative influence of environmental preferences and functional traits on genetic diversity and gene flow. The results indicate that only in three species geographic structuring of haplotype distribution reflects a north vs. south of the BMC pattern. Environmental factors linked with altitude were recognized as affecting genetic trends, but the selective processes operating on upland species appear to be associated with competitiveness and regeneration opportunities on poor soil types rather than climate variables alone. In contrast to previous observations within southeastern Australian rainforests, genetic differentiation in the AWT appears to be associated with small-fruited rather than large-fruited species, highlighting how external factors can influence the dispersal dimension. Overall, this study emphasizes the importance of considering functional and environmental factors when attempting generalizations on landscape-level patterns of genetic variation. Understanding how plant functional groups respond to environmental and climatic heterogeneity can help us predict responses to future change.


Asunto(s)
Elaeocarpaceae/genética , Ambiente , Genética de Población , Árboles/genética , Alelos , Australia , ADN de Plantas/genética , Evolución Molecular , Flujo Génico , Marcadores Genéticos , Variación Genética , Geografía , Haplotipos , Repeticiones de Microsatélite , Dinámica Poblacional , Análisis de Componente Principal , Análisis de Secuencia de ADN , Clima Tropical
9.
Genetics ; 157(2): 765-75, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11156995

RESUMEN

The nonA gene of Drosophila melanogaster is important for normal vision, courtship song, and viability and lies approximately 350 bp downstream of the dGpi1 gene. Full rescue of nonA mutant phenotypes can be achieved by transformation with a genomic clone that carries approximately 2 kb of 5' regulatory material and that encodes most of the coding sequence of dGpi1. We have analyzed this 5' region by making a series of deleted fragments, fusing them to yeast GAL4 sequences, and driving UAS-nonA expression in a mutant nonA background. Regions that both silence and enhance developmental tissue-specific expression of nonA and that are necessary for generating optomotor visual responses are identified. Some of these overlap the dGpi1 sequences, revealing cis-regulation by neighboring gene sequences. The largest 5' fragment was unable to rescue the normal electroretinogram (ERG) consistently, and no rescue at all was observed for the courtship song phenotype. We suggest that sequences within the nonA introns that were missing in the UAS-nonA cDNA may carry enhancer elements for these two phenotypes. Finally, we speculate on the striking observation that some of the cis-regulatory regions of nonA appear to be embedded within the coding regions of dGpi1.


Asunto(s)
Proteínas de Drosophila , Drosophila melanogaster/genética , Proteínas Nucleares/genética , Alelos , Animales , Animales Modificados Genéticamente , Conducta Animal , Electrorretinografía , Embrión no Mamífero/metabolismo , Elementos de Facilitación Genéticos , Femenino , Galactósidos/metabolismo , Eliminación de Gen , Regulación de la Expresión Génica , Genotipo , Inmunohistoquímica , Indoles/metabolismo , Intrones , Larva/metabolismo , Masculino , Modelos Genéticos , Ovario/metabolismo , Fenotipo , Células Fotorreceptoras de Invertebrados/fisiología , Regiones Promotoras Genéticas , Proteínas Recombinantes de Fusión/metabolismo , Distribución Tisular , Caminata
10.
Theor Appl Genet ; 104(1): 61-6, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12579429

RESUMEN

Three EST-derived microsatellite loci from Vitis vinifera were amplified and sequenced across eight species of Vitaceae from four different genera. Phylogenetic analysis of the microsatellite's flanking regions produced informative results in congruence with previous studies. Generic relationships were respected and the data produced sufficient inter-specific variation to distinguish between Cayratia acris and Cayratia saponaria, two very closely related species. Overall, the sequence alignments showed that priming sites were conserved, whereas microsatellite repeats were present in most cases but structurally variable. The sequence data provided information on the evolutionary patterns of various microsatellite repeats and their correlation to evolutionary relationships among taxa.

11.
Free Radic Res ; 35(6): 933-9, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11811544

RESUMEN

A stable ESR signal, centred at g = 2.0037 +/- 0.0002, characterised by a single resonance and assignable to a free radical, was found in all the bottled red wines, both commercial and experimental, that we have examined. The radical concentration was calculated to be in the range of 5-82 nM. After exposure of the wines to air for a few minutes a two fold increase of the ESR signal, followed by a slow decrease with time, was observed. The intensity of ESR signal in experimental red wines, was found to increase with the ageing of the wines and was strictly correlated to the total content of polyphenols. The formation of semiquinone radicals of polyphenols is suggested as one possible mechanism leading to the presence of stable free radicals in red wines.


Asunto(s)
Flavonoides , Radicales Libres/análisis , Radicales Libres/química , Vino/análisis , Espectroscopía de Resonancia por Spin del Electrón , Humanos , Fenoles/análisis , Fenoles/química , Polímeros/análisis , Polímeros/química , Polifenoles , Factores de Tiempo
12.
J Agric Food Chem ; 48(6): 1996-2002, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10888488

RESUMEN

Highly reactive radicals, ROO(*), were generated from 2, 2'-azobis[2-(2-imidazolin-2-yl)propane] and linoleic acid. The ROO(*) scavenging capacity of some Italian red wines was evaluated following the changes in oxygen consumption. Under the experimental conditions the time course of oxygen consumption shows two typical behaviors: trolox-like (class I) and gallic acid-like (class II). Usually the time course of wine was similar to that of gallic acid. The rate of oxygen consumption was found to decrease exponentially with the amount of wine or gallic acid added to the test solution. On this basis the capacity of red wines to scavenge peroxy radicals was expressed as content of gallic acid (S(GA)). The S(GA) values were found to be correlated to the amount of total proanthocyanidins and total polyphenols of some Italian red wines (p < 0.01). The proanthocyanidins extracted from seeds were shown to make a major contribution to the peroxy radical scavenging capacity of red wines, whereas, interestingly, the chemical class of the low molecular weight tannins reactive to vanillin did not correlate with the S(GA) values.


Asunto(s)
Antocianinas/química , Antioxidantes , Depuradores de Radicales Libres , Peróxidos/química , Proantocianidinas , Vino , Italia
13.
Drugs Exp Clin Res ; 25(4): 167-71, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10442273

RESUMEN

L-carnitine is essential to cellular energy production mainly because of its acyl- and acetyl-carrier properties. Athletes commonly take L-carnitine, which is thought to improve exercise performance. There are no reports on carnitine plasma concentrations and carnitine excretion in short-duration maximal exercise in well-trained athletes taking this substance. We measured plasma and urine carnitine concentrations before and 10 min after maximal treadmill ergometry in nine well-trained sportsmen with and without oral supplementation with 1 g L-carnitine. In athletes without L-carnitine intake, plasma free carnitine concentration decreased significantly from 45.2 +/- 5.3 to 41.6 +/- 5.0 mumol/l (mean +/- SD, p < 0.001) 10 min after exercise compared with baseline. In athletes with oral L-carnitine supplementation, plasma free carnitine concentration at baseline was 71.3 +/- 10.2 mumol/l and did not change after maximal exercise (71.8 mumol/l +/- 10.7 mumol/l). The elevated plasma concentration of free carnitine without decrease after maximal exercise in well-trained athletes taking L-carnitine could be important in view of the newly postulated direct vascular effects of L-carnitine in improving skeletal muscle performance.


Asunto(s)
Carnitina/metabolismo , Suplementos Dietéticos , Ejercicio Físico/fisiología , Medicina Deportiva , Administración Oral , Adulto , Carnitina/sangre , Carnitina/orina , Estudios de Casos y Controles , Humanos , Valores de Referencia , Descanso
14.
Ultrasonics ; 40(1-8): 205-10, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12159933

RESUMEN

The paper deals with ultrasonic testing of adhesive joints between sheets of thickness greater than 1 mm, bonded by a "zero thickness" layer of anaerobic adhesive. In the case of equally thick sheets, interference phenomena can arise that make impossible the use of the "decay method" (a method previously developed by the authors for the case of non-zero adhesive thickness). Consequently an alternative method, termed "first peak", has been proposed. In order to evaluate the applicability of the two methods, a series of tests has been carried out on specimens having geometry suitable for both types of inspection. Also two different levels of surface roughness have been considered. The results allow for evaluating the defect detection capability of each method, accounting for the roughness effect, and give information on the suitable control procedures.

15.
Mol Ecol Resour ; 14(1): 199-208, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24119022

RESUMEN

Standardized phylogeographic studies across codistributed taxa can identify important refugia and biogeographic barriers, and potentially uncover how changes in adaptive constraints through space and time impact on the distribution of genetic diversity. The combination of next-generation sequencing and methodologies that enable uncomplicated analysis of the full chloroplast genome may provide an invaluable resource for such studies. Here, we assess the potential of a shotgun-based method across twelve nonmodel rainforest trees sampled from two evolutionary distinct regions. Whole genomic shotgun sequencing libraries consisting of pooled individuals were used to assemble species-specific chloroplast references (in silicio). For each species, the pooled libraries allowed for the detection of variation within and between data sets (each representing a geographic region). The potential use of nuclear rDNA as an additional marker from the NGS libraries was investigated by mapping reads against available references. We successfully obtained phylogeographically informative sequence data from a range of previously unstudied rainforest trees. Greater levels of diversity were found in northern refugial rainforests than in southern expansion areas. The genetic signatures of varying evolutionary histories were detected, and interesting associative patterns between functional characteristics and genetic diversity were identified. This approach can suit a wide range of landscape-level studies. As the key laboratory-based steps do not require prior species-specific knowledge and can be easily outsourced, the techniques described here are even suitable for researchers without access to wet-laboratory facilities, making evolutionary ecology questions increasingly accessible to the research community.


Asunto(s)
ADN de Cloroplastos/genética , Variación Genética , Genoma de Planta , Filogeografía , Árboles/genética , Biología Computacional , Secuenciación de Nucleótidos de Alto Rendimiento , Análisis de Secuencia de ADN
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